Field of the Invention
The present disclosure relates to control of an image forming apparatus, and more particularly to control of the fan included in an image forming apparatus.
Description of the Related Art
Electrophotographic image forming apparatuses are commonly used. An electrophotographic image forming apparatus includes a fixing device. The fixing device fuses a toner image by heat to fix the toner image on a print material. In connection with a technique for adjusting the temperature for fixing a toner image on a print material, Japanese Laid-Open Patent Publication No. 2012-242635 discloses an image forming apparatus in which “the surface temperature of the heating member can be maintained in STANDBY mode within a range of setting temperatures without causing temperature overshoot or undershoot”.
The temperature inside an image forming apparatus may be increased by heat generated from the fixing device. This may cause a failure in a device inside the image forming apparatus. The heat generated from the fixing device therefore should be discharged from the image forming apparatus. An example of the device that discharges heat inside an image forming apparatus is a fan. The fan reduces the temperature inside the image forming apparatus or the fixing device by blowing air to heat in the conveyance path of a print material from the fixing device or the power supply board. In connection with control of the fan, Japanese Laid-Open Patent Publication No. 2008-145599 discloses an image forming apparatus in which “the fan motor is allowed to operate only when necessary”.
When the fan is allowed to operate unnecessarily, electricity is wasted and/or noise is generated. It is therefore preferable to minimize the operation of the fan.
The image forming apparatus disclosed in Japanese Laid-Open Patent Publication No. 2008-145599 reduces the operation time of the fan motor after a print operation is finished, if the number of printed sheets is small. This is because if the number of printed sheets is small, the temperature inside the apparatus is not increased much. Unfortunately, the image forming apparatus always allows the fan to operate after a print operation is finished, and allows unnecessary operation of the fan.